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Effects of Fatigue on Strength and Rapid Force Characteristics Between Traditional and Explosive Resistance-trained Males

Mackey, Cameron
Examine the effects of fatigue on maximal strength and rapid force between traditional (TRT) and explosive (ERT) resistance-trained males, following upper (UE) and lower extremity (LE) fatigue protocols. METHODS: Twelve TRT (mean�SD: age=24.5�2.94years, height=178.54�5.64cm, mass=93.28�15.07kg) and eight ERT (mean�SD: age=22�2.39years, height=177.8�5.43cm, mass=80.74�7.22kg) males visited the laboratory on 2 occasions, separated by 2-3 days. The first visit included classifying participants as TRT or ERT, determined by their self-reported training status. Participants were familiarized with the isometric and isokinetic maximal voluntary contractions (MVCs) of the UE [Elbow Flexors (EF) and Extensors (EE)] and LE [Knee Flexors (KF) and Extensors (KE)] testing protocols. During the second visit, participants performed the isokinetic protocols (50 repetitions at 180��s-1) for the UE and LE, in randomized order, with a 20 minute rest period between protocols. Prior to (Pre) and immediately following (Post) the protocols, isometric and isokinetic MVCs were completed in order to assess peak torque (PT), peak velocity (Vmax), acceleration (ACC), and fatigue index (FI). Separate 2-way mixed factorial ANOVAs were performed for each dependent variable. An alpha level of p?0.05 was utilized to determine statistical significance. RESULTS: There was no significant group � time interaction for ACC (p=0.196-0.903), PT (p=0.128-0.429), Vmax (p=0.150-0.996), nor a group � muscle interaction for FI (p=0.095-0.536). However, a main effect for group (p=0.030) was revealed in which the TRT group had a higher PT compared to the ERT group for the EF. Furthermore, significant main effects for time (p?0.002) was observed, in which ACC, PT, and Vmax were significantly lower a Post compared to Pre for all muscle groups except for PT of the knee extensors. Additionally, FI was greater in the EF (p=0.001-0.016) compared to all other muscles for ACC and Vmax; however, EF FI of PT was greater only when compared to the knee extensors (p=0.022). CONCLUSIONS: An isokinetic fatigue protocol of the UE and LE had similar effects on TRT and ERT individuals. Although specific muscles were affected differently, it is possible this is due to the lack of specificity with the isokinetic testing modality and the participant training status.